When $1 \ g$ each of compounds $AB$ and $AB_2$ are dissolved in $15 \ g$ of water separately,they increase the boiling point of water by $2.7 \ K$ and $1.5 \ K$ respectively. The atomic mass of $A$ (in $amu$) is $........ \times 10^{-1}$ (Nearest integer). (Given: Molal boiling point elevation constant $K_b = 0.5 \ K \ kg \ mol^{-1}$)

The osmotic pressure of $0.1 \ M$ monobasic acid of $pH \ 3$ at $27^{\circ} C$ is (in $atm$)

$1 \ g$ of silver gets distributed between $10 \ cm^3$ of molten zinc and $100 \ cm^3$ of molten lead at $800^{\circ} C$. The percentage of silver in the zinc layer is approximately

The number of pairs of solutions having the same value of osmotic pressure from the following is:
(Assume $100\%$ ionization)
$A.$ $0.500 \ M \ C_2H_5OH \ (aq)$ and $0.25 \ M \ KBr \ (aq)$
$B.$ $0.100 \ M \ K_4[Fe(CN)_6] \ (aq)$ and $0.100 \ M \ FeSO_4(NH_4)_2SO_4 \ (aq)$
$C.$ $0.05 \ M \ K_4[Fe(CN)_6] \ (aq)$ and $0.25 \ M \ NaCl \ (aq)$
$D.$ $0.15 \ M \ NaCl \ (aq)$ and $0.1 \ M \ BaCl_2 \ (aq)$
$E.$ $0.02 \ M \ KCl \cdot MgCl_2 \cdot 6H_2O \ (aq)$ and $0.05 \ M \ KCl \ (aq)$

The difference between the boiling point and freezing point of an aqueous solution of urea containing $10.0 \ kg$ of water is $100.2372 \ ^oC$. How many grams of urea are dissolved in the solution? (Given: $K_b = 0.513 \ K \ kg \ mol^{-1}$,$K_f = 1.86 \ K \ kg \ mol^{-1}$)

$A$ substance '$X$' $(1.5 \ g)$ dissolved in $150 \ g$ of a solvent '$Y$' (molar mass $= 300 \ g \ mol^{-1}$) led to an elevation of the boiling point by $0.5 \ K$. The relative lowering in the vapour pressure of the solvent '$Y$' is . . . . . . $\times 10^{-2}$. (Nearest integer)
[Given : $K_{b}$ of the solvent $= 5.0 \ K \ kg \ mol^{-1}$]
Assume the solution to be dilute and no association or dissociation of $X$ takes place in solution.